JPH11343955A - Hydraulic turbine and reversible pump-turbine - Google Patents

Hydraulic turbine and reversible pump-turbine

Info

Publication number
JPH11343955A
JPH11343955A JP10153031A JP15303198A JPH11343955A JP H11343955 A JPH11343955 A JP H11343955A JP 10153031 A JP10153031 A JP 10153031A JP 15303198 A JP15303198 A JP 15303198A JP H11343955 A JPH11343955 A JP H11343955A
Authority
JP
Japan
Prior art keywords
blade
turbine
runner
tmax
pump
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10153031A
Other languages
Japanese (ja)
Inventor
Yuji Tanaka
雄司 田中
Masami Harano
正実 原野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP10153031A priority Critical patent/JPH11343955A/en
Publication of JPH11343955A publication Critical patent/JPH11343955A/en
Pending legal-status Critical Current

Links

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/20—Hydro energy

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  • Hydraulic Turbines (AREA)

Abstract

PROBLEM TO BE SOLVED: To prevent cavitation at the vane inlet of a runner when at the time of hydraulic wheel operation even in case where the ratio of the maximum head at the time of pumping operation to the min. head at the time of hydraulic wheel operation is large and to enhance the pumping efficiency and hydraulic turbine efficiency. SOLUTION: This hydraulic turbine is structured so that a plurality of vanes 1c provided around a rotary shaft are held by a runner crown and a runner band and that runners 1 having passage 1w are installed between the vanes 1c. A swelling for preventing exfoliation of a water stream flowing along the rear surface 1p of each vane 1c is provided between the position Q as the shortest distance from the blade 1c front edge P positioned at the forefront with respect to the water stream at the time of hydraulic wheel operation to its adjacent vane 1c' preceding in the rotating direction at the time of hydraulic wheel operation and the front edge P of the adjacent vane.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は水車及びポンプ水車
に係り、特に水車運転時のランナ入口のキャビテーショ
ンの発生を抑制した水車及びポンプ水車に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine and a pump turbine, and more particularly to a turbine and a pump turbine in which the occurrence of cavitation at the runner entrance during the operation of the turbine is suppressed.

【０００２】[0002]

【従来の技術】まず、図９ないし図１１を参照して本発
明の従来技術について説明する。2. Description of the Related Art First, the prior art of the present invention will be described with reference to FIGS.

【０００３】図９は揚水発電所に用いられる一般的なポ
ンプ水車の断面図である。図９において、ポンプ水車
は、供給される水によって回転駆動力を得て回転するラ
ンナ１と、ランナ１に水流を導く開口比が可変のガイド
ベーン２と、ガイドベーン２に水流を導く開口比が固定
のステーベーン３と、これらの各部を内包するとともに
流路を形成するケーシング４と、電力の変換を行なう回
転機の回転軸５と、吸い出し管６とから基本的に構成さ
れている。水車運転時は水流が上池から導水路を通って
ケーシング４に流入し、ステーベーン３、ガイドベーン
２を通りランナ１へ流入して、ランナ１を回転駆動し吸
出し管６より放水路を通って下池に流出する。一方、ポ
ンプ運転時は発電電動機で水車運転と逆に回転駆動され
たランナ１により、水流は下池から放水路を通って吸出
し管６へ流入し、ランナ１、ガイドベーン２、ステーベ
ーン３、ケーシング４を通過し、導水路を通って上池に
押し上げられる。FIG. 9 is a sectional view of a general pump-turbine used in a pumped storage power plant. In FIG. 9, the pump turbine includes a runner 1 that rotates by obtaining a rotational driving force by supplied water, a guide vane 2 having a variable opening ratio for guiding a water flow to the runner 1, and an opening ratio for guiding a water flow to the guide vane 2. Is basically constituted by a stationary vane 3, a casing 4 containing these parts and forming a flow path, a rotating shaft 5 of a rotating machine for converting electric power, and a suction pipe 6. During the operation of the water wheel, the water flows from the upper pond to the casing 4 through the headrace, flows into the runner 1 through the stay vanes 3 and the guide vanes 2, drives the runner 1 to rotate, and passes through the drain pipe 6 from the suction pipe 6. Spills into the lower pond. On the other hand, during the pump operation, the water flow flows from the lower pond to the suction pipe 6 through the water discharge channel by the runner 1 rotated in the opposite direction to the water turbine operation by the generator motor, and the runner 1, the guide vane 2, the stay vane 3, and the casing 4 And is pushed up to the upper pond through the headrace.

【０００４】水車運転時、ポンプ運転時ともに導水路、
水車内部、放水路において水力損失が発生する。ポンプ
運転時は下池から上池へ水を押し上げなければならない
から、ランナ１で発生しなければならない実質揚程は上
池と下池の水位差に水力損失を加えたものになる。した
がって、ランナ１は前記実質揚程に適合するように作ら
れる。一方、水車運転時は水流によりランナ１がポンプ
運転時とは逆に回転駆動される。このとき、ランナ１に
作用する実質落差は上池と下池の水位差から水力損失を
差し引いたものになる。ポンプ水車は前記実質揚程に適
合するように作られたランナ１により水車運転を行うの
で、図１０に示すように水車運転で使用する運転領域は
水車の最高効率点よりも低落差側になる。[0004] In both the operation of the water turbine and the operation of the pump, the headrace channel,
Hydraulic loss occurs inside the water turbine and in the discharge channel. During pump operation, water must be pushed up from the lower pond to the upper pond, so the actual head that must be generated in the runner 1 is the difference in water level between the upper and lower ponds plus the hydraulic loss. Therefore, the runner 1 is made to fit the substantial head. On the other hand, during the operation of the water wheel, the runner 1 is rotationally driven by the water flow in a direction opposite to that during the operation of the pump. At this time, the actual head acting on the runner 1 is obtained by subtracting the hydraulic loss from the water level difference between the upper and lower ponds. Since the pump-turbine is operated by the runner 1 adapted to the above-mentioned substantial head, the operation area used in the operation of the turbine is lower than the highest efficiency point of the turbine as shown in FIG.

【０００５】[0005]

【発明が解決しようとする課題】ところで、近年のポン
プ水車は高落差化に伴い、導水路、放水路がこれまでに
比べ長くなるため、導水路、放水路の水力損失が増大す
る。その結果、ポンプ運転時に要求される最高揚程Ｈpm
axと水車運転時に要求される最低落差Ｈtminの比である
変落差比Ｈpmax／Ｈtminが大きくなり、従来技術のポン
プ水車では水車運転時の低落差状態でランナ入口にキャ
ビテーションが発生するという問題がある。However, in recent years, pump heads have been increased in height and headraces and tailraces have become longer than before, so that hydraulic power loss in headraces and tailraces has increased. As a result, the maximum head Hpm required during pump operation is
The variable head ratio Hpmax / Htmin, which is the ratio of ax to the minimum head Htmin required during operation of the turbine, becomes large, and the conventional pump-turbine has a problem that cavitation is generated at the runner inlet in a low head state during operation of the water turbine. .

【０００６】図１１に水車運転時のランナ入口速度三角
形を示す。図１１に示す羽根形状は図９におけるランナ
のＡ−Ａ線断面図である。同図から分かるように低落差
状態では水流が相対流れＷで羽根１ｃに流入するため、
羽根角度βbは流れ角度βより大きくなる。このように
変落差比が大きくなると流れ角度βはますます小さくな
るため羽根角度βb との差が大きくなる。その結果、水
流は羽根１ｃの回転方向に対し後面１ｐに沿って流れる
ことができなくなり、羽根後面１ｐから剥離して渦が生
ずる。そして、この渦の中心では圧力が低下し、キャビ
テーションが発生する。FIG. 11 shows a runner entrance speed triangle during operation of a water turbine. The blade shape shown in FIG. 11 is a sectional view taken along line AA of the runner in FIG. As can be seen from the figure, in the low head state, the water flow flows into the blade 1c with the relative flow W,
The blade angle βb becomes larger than the flow angle β. in this way
As the falling head ratio increases, the flow angle β becomes smaller and smaller, and the difference from the blade angle βb increases. As a result, the water flow cannot flow along the rear surface 1p in the rotation direction of the blade 1c, and separates from the blade rear surface 1p to generate a vortex. Then, the pressure decreases at the center of the vortex, and cavitation occurs.

【０００７】従来技術ではこのような場合羽根角度βb
を小さくするが、そうすると高落差状態での 水流の相
対流れＷ’に対しては前記羽根角度βbが流れ角度β’
より小さくなる。即ち、前記低落差状態と逆の関係にな
り、同様の理由により羽根１ｃの回転方向に対し、前面
１ｓにキャビテーションが発生する。この前面１ｓに発
生するキャビテーションを抑制する技術として、例えば
特開平５−２７２４４４号公報記載の発明が知られてい
る。この発明は、羽根前面１ｓとランナバンド１ｂの付
け根部分の曲率半径を大きくしたことを特徴としてい
る。In the prior art, in such a case, the blade angle βb
, The blade angle βb is equal to the flow angle β ′ with respect to the relative flow W ′ of the water flow in the high head state.
Smaller. In other words, the relationship is opposite to the low drop state, and for the same reason, cavitation occurs on the front surface 1s in the rotation direction of the blade 1c. As a technique for suppressing the cavitation generated on the front surface 1s, for example, the invention described in Japanese Patent Application Laid-Open No. 5-272444 is known. The present invention is characterized in that the radius of curvature at the root of the blade front surface 1s and the runner band 1b is increased.

【０００８】しかし、このような形状の羽根をポンプ水
車に適用すると、ポンプ運転時に水流が前記付け根部分
を通過するとき、付け根部分の頂部に至るまでは増速
し、頂部から後縁の間は急減速する。その結果、羽根前
面１ｓの境界層が厚くなるので、羽根１ｃの後流が大き
くなって水力損失が増加し、その結果、ポンプ効率が低
下する。また、前記付け根部では水車の回転方向に対し
て先行する隣の羽根の後面１ｐとの間で形成される羽根
間通路幅Ｓが小さくなるため、水車運転時は付け根部の
流速が増大して水力損失が増加し、その結果、水車効率
が低下する。However, when the blade having such a shape is applied to a pump turbine, when the water flow passes through the root portion during pump operation, the speed increases up to the top of the root portion, and between the top and the trailing edge, the speed increases. Suddenly decelerate. As a result, the boundary layer of the front surface 1s of the blade is thickened, so that the wake behind the blade 1c is increased and hydraulic power loss is increased, and as a result, pump efficiency is reduced. In addition, at the root portion, the inter-blade passage width S formed between the front surface 1p of the next blade and the preceding blade in the rotation direction of the turbine becomes smaller, so that the flow speed at the root portion increases during the operation of the turbine. Hydropower losses increase, resulting in reduced turbine efficiency.

【０００９】他の従来技術として特開平１−２９９８９
号公報に記載された発明も知られている。この発明は、
羽根の前縁をランナバンド１ｂからランナクラウン１ａ
にかけて水車運転時のランナ回転方向に対し後退させ、
ランナバンド１ｂとランナクラウン１ａの間の水流の流
量配分を変えることによりキャビテーション性能を改善
しているが、ランナへ流入する水流の落差変化に伴う前
記流れ角度βの変化に対しては、キャビテーションを抑
制する効果を得ることができない。Another prior art is disclosed in Japanese Patent Application Laid-Open No. 1-29989.
Is also known. The present invention
The leading edge of the blade is changed from the runner band 1b to the runner crown 1a.
Toward the runner rotation direction during water turbine operation,
Although the cavitation performance is improved by changing the flow rate distribution of the water flow between the runner band 1b and the runner crown 1a, the cavitation is suppressed with respect to the change in the flow angle β caused by the change in the head flow of the water flowing into the runner. The effect of suppression cannot be obtained.

【００１０】このように高落差ポンプ水車では、変落差
比が大きくなるため水車運転時の低落差側でランナの羽
根入口にキャビテーションが発生するという問題があ
る。また、従来技術でキャビテーションを抑制しようと
すると、ポンプ効率、水車効率が低下するという問題が
ある。As described above, in the high head pump turbine, there is a problem that cavitation is generated at the inlet of the runner blade on the low head side during the operation of the water turbine because the head ratio becomes large. In addition, there is a problem that the pump efficiency and the water turbine efficiency decrease when trying to suppress cavitation by the conventional technology.

【００１１】本発明は、このような従来技術の問題点に
鑑みてなされたもので、その目的は、変落差比が大きい
場合でも水車運転時にランナの羽根入口にキャビテーシ
ョンが発生せず、かつ、ポンプ効率、水車効率も低下し
ない水車及びポンプ水車を提供することにある。The present invention has been made in view of such problems of the prior art, and an object thereof is to prevent cavitation from occurring at a runner blade inlet during operation of a water turbine even when a head-to-head ratio is large, and An object of the present invention is to provide a turbine and a pump turbine that do not reduce the pump efficiency and the turbine efficiency.

【００１２】[0012]

【課題を解決するための手段】前記目的を達成するた
め、第１の手段は、ランナクラウン及びランナバンドに
よって回転軸の回りに複数枚配置された羽根を保持し、
各羽根間に流路を有するランナを備えた水車及びポンプ
水車において、前記羽根の水車運転時の水流に対して最
先端に位置する前縁部から水車運転時の回転方向に先行
する隣接した羽根に対して最短距離に当たる位置と、当
該隣接した羽根の前縁部との間に羽根の後面に沿って流
れる水流の剥離を防止するための膨らみ部を設けたこと
を特徴とする。In order to achieve the above object, a first means is to hold a plurality of blades arranged around a rotation axis by a runner crown and a runner band,
In a water turbine and a pump water turbine provided with a runner having a flow path between each blade, adjacent blades that precede in a rotation direction during the operation of the turbine from a leading edge positioned at the foremost position with respect to the water flow of the blade during the operation of the turbine. And a bulging portion for preventing separation of the water flow flowing along the rear surface of the blade between the position corresponding to the shortest distance and the front edge of the adjacent blade.

【００１３】第２の手段は、第１の手段において、前記
膨らみ部の羽根厚みが最大となる頂部から前記最短距離
に当たる位置までの前記羽根後面に変曲点を備えている
ことを特徴とする。The second means is characterized in that, in the first means, an inflection point is provided on a rear surface of the blade from the top where the blade thickness of the bulging portion is maximum to a position corresponding to the shortest distance. .

【００１４】第３の手段は、第１の手段において、前記
膨らみ部の羽根厚みが最大となる頂部の羽根厚みをＴma
x、前記羽根前縁から前記頂部までの長さをＬmax、水車
運転時の水流に対し前記頂部の下流側で羽根厚みが前記
頂部の羽根厚みＴmaxの７５%に戻る部分と前記羽根前縁
までの長さをＬ75としたとき、前記長さＬmaxと前記羽
根厚みＴmaxの比が、 Ｌmax／Ｔmax≦６ であり、前記長さＬ75と前記羽根厚みＴmaxとの比が、 ４≦Ｌ75／Ｔmax＜１０ であり、かつ、前記長さＬ75とＬmaxとの比が、 Ｌ75＞ Ｌmax となるように前記長さＬmax、Ｌ75及び羽根厚みＴmaxが
設定されていることを特徴とする。A third means is the first means, wherein the thickness of the top blade at which the thickness of the bulge is maximum is Tma.
x, the length from the leading edge of the blade to the top portion is Lmax, and the portion of the blade thickness that returns to 75% of the blade thickness Tmax of the top portion on the downstream side of the top portion with respect to the water flow during the operation of the turbine and the leading edge of the blade. When the length is L75, the ratio between the length Lmax and the blade thickness Tmax is Lmax / Tmax ≦ 6, and the ratio between the length L75 and the blade thickness Tmax is 4 ≦ L75 / Tmax < 10, and the lengths Lmax and L75 and the blade thickness Tmax are set such that the ratio of the lengths L75 and Lmax satisfies L75> Lmax.

【００１５】第４の手段は、第３の手段において、前記
頂部の羽根厚みTmaxが、前記ランナクラウンと前記ラン
ナバンドの間で連続的に変化していることを特徴とす
る。According to a fourth aspect, in the third aspect, the blade thickness Tmax at the top portion is continuously changed between the runner crown and the runner band.

【００１６】第５の手段は、第３の手段において、前記
長さLmaxが、前記ランナクラウンと前記ランナバンドの
間で連続的に変化していることを特徴とする。A fifth means is the third means, wherein the length Lmax changes continuously between the runner crown and the runner band.

【００１７】このように構成すると、回転軸の周りに複
数枚配置された羽根の水車回転方向に対し後面に膨らみ
部を設けてあるので、周方向と前記羽根後面とでなす羽
根角度が小さくなる。その結果、変落差比が大きい水車
低落差状態においても流れ角度と前記羽根角度の差が小
さくなり水流は前記羽根後面に沿ってスムーズに流れる
ので、水流が前記羽根後面より剥離することがなく渦が
発生しない。これにより、前記羽根後面の圧力低下が抑
制されてキャビテーションが発生しない。According to this structure, since a plurality of blades arranged around the rotation axis are provided with a bulging portion on the rear surface in the rotating direction of the water turbine, the blade angle between the circumferential direction and the rear surface of the blade is reduced. . As a result, even in the low-fall state of the turbine, where the head ratio is large, the difference between the flow angle and the blade angle is small, and the water flow smoothly flows along the rear surface of the blade, so that the water flow does not separate from the rear surface of the blade and Does not occur. Thereby, the pressure drop on the rear surface of the blade is suppressed, and cavitation does not occur.

【００１８】また、ポンプ運転時の羽根後面の流れは、
ポンプ流れでみたときの羽根後半部では増速傾向にある
ので、膨らみ部が流れに及ぼす影響はほとんどない。そ
の結果、膨らみ部を設けてもポンプ運転時に水力損失が
増加することはない。The flow behind the blades during pump operation is as follows:
Since the speed tends to increase in the latter half of the blade when viewed from the pump flow, the bulging portion has almost no effect on the flow. As a result, even when the bulging portion is provided, the hydraulic power loss does not increase during the operation of the pump.

【００１９】さらに、羽根後面に膨らみ部を設けてあ
り、羽根前面には膨らみ部がないので、羽根前面と水車
回転方向に対して先行する隣の羽根の後面とで形成され
る羽根間通路幅が小さくならない。これにより、水車運
転時の流速は増大しないので水力損失も増加しない。Further, since a bulging portion is provided on the rear surface of the blade, and there is no bulging portion on the front surface of the blade, a passage width between the blades formed by the front surface of the blade and the rear surface of an adjacent blade preceding the rotating direction of the turbine. Does not become smaller. As a result, the flow velocity during the operation of the turbine does not increase, so that the hydraulic power loss does not increase.

【００２０】[0020]

【発明の実施の形態】以下、図面を参照し、本発明の実
施形態について説明する。なお、以下の説明において、
前述の従来例と同等な各部には同一の参照符号を付し、
重複する説明は割愛する。Embodiments of the present invention will be described below with reference to the drawings. In the following description,
The same parts as those in the conventional example described above are denoted by the same reference numerals,
Duplicate descriptions are omitted.

【００２１】図１は本発明の一実施形態に係るポンプ水
車のランナ羽根形状を示す断面図で、図９に示すランナ
をＡ−Ａ線で断面した図である。羽根１ｃは回転軸５の
周りに複数枚配置されており、水流の相対流れに対して
最先端の位置を前縁Ｐとすると、この前縁Ｐを境に前述
のように前面１ｓと後面１ｐとに分けられる。なお、こ
こにおける前面１ｓと後面１ｐは水車運転時の回転方向
に対して前縁Ｐを基準に前側の面であるか後側の面であ
るかというで規定している。各羽根１ｃについて同様で
あるが、図において中央の羽根１ｃの羽根前面１ｓと回
転方向に対し先行する隣の羽根１ｃ’の羽根後面１ｐと
の間には羽根間流路１ｗが形成されている。前記羽根１
ｃの前縁Ｐと隣接する羽根１ｃ’の後面１ｐ間には羽根
間流路１ｗが最短距離Ｓとなる位置Ｑがある。そして、
この隣接する羽根１ｃ’の前記位置Ｑと前記前縁Ｐの間
の羽根後面１ｐに本発明の特徴である膨らみ部Ｂが形成
されている。FIG. 1 is a sectional view showing the shape of a runner blade of a pump-turbine according to an embodiment of the present invention. FIG. 1 is a sectional view of the runner shown in FIG. A plurality of blades 1c are arranged around the rotation axis 5. When the leading edge position relative to the relative flow of the water flow is the front edge P, the front surface 1s and the rear surface 1p are separated from the front edge P as described above. And divided into In addition, the front surface 1s and the rear surface 1p here are defined as a front surface or a rear surface with respect to the front edge P with respect to the rotation direction during the operation of the turbine. The same applies to each blade 1c, except that a blade-to-blade flow path 1w is formed between the blade front surface 1s of the central blade 1c and the blade rear surface 1p of the next adjacent blade 1c 'in the rotation direction. . The wing 1
Between the leading edge P of c and the rear surface 1p of the adjacent blade 1c ', there is a position Q where the inter-blade flow path 1w is the shortest distance S. And
A bulge B, which is a feature of the present invention, is formed on the rear surface 1p of the blade between the position Q and the front edge P of the adjacent blade 1c '.

【００２２】この膨らみ部Ｂは図２に示すように曲率半
径ｒ１，ｒ２，ｒ３の三つの円弧で構成されており、各
々の円弧の接点は変曲点となっている。また、膨らみ部
Ｂは羽根厚みが最大となる頂部Ｒの羽根厚みをＴmax、
羽根前縁Ｐから頂部Ｒまでの長さをＬmaxとし、水車運
転時の水流に対し頂部Ｒの下流側で当該頂部Ｒの羽根厚
みの７５％に戻る部分と羽根前縁Ｐまでの長さをＬ75と
したとき、 Ｌmax／Ｔmax＝３ かつ、 Ｌ75／Ｔmax＝５ になるように寸法関係が設定されている。As shown in FIG. 2, the bulging portion B is composed of three arcs having radii of curvature r1, r2, and r3, and the contact point of each arc is an inflection point. In addition, the bulging portion B sets the blade thickness of the top portion R at which the blade thickness is maximum to Tmax,
The length from the blade leading edge P to the top R is defined as Lmax, and the length of the portion returning to 75% of the blade thickness of the top R at the downstream side of the top R with respect to the water flow during the operation of the turbine and the length of the blade leading edge P are determined. When L75 is set, the dimensional relationship is set so that Lmax / Tmax = 3 and L75 / Tmax = 5.

【００２３】このように構成すると、図３に示すように
羽根後面１ｐの羽根角度βbが従来技術の羽根角度βb0
に比べ小さくなる。したがって、水車運転時の低落差状
態でも水流の相対流れＷの流れ角度βとの差が小さくな
る。その結果、水流は羽根後面１ｐに沿って剥離するこ
となく流れることができる。その結果、羽根後面１ｐの
圧力低下が抑制され、羽根後面１ｐでキャビテーション
が生じることはない。With this configuration, as shown in FIG. 3, the blade angle βb of the blade rear surface 1p is changed to the conventional blade angle βb0.
Smaller than. Therefore, the difference between the relative angle W of the water flow and the flow angle β of the water flow becomes small even in the low head state during the operation of the water wheel. As a result, the water flow can flow along the rear surface 1p of the blade without separating. As a result, the pressure drop at the blade rear surface 1p is suppressed, and cavitation does not occur at the blade rear surface 1p.

【００２４】前記膨らみ部Ｂの構成における最大羽根厚
みＴmaxは、羽根１ｃのランナクラウン１ａ側とランナ
バンド１ｂ側の間で一定である必要はなく、水車の仕様
に適合するように連続的に変化させ、所定の分布を持た
せても良い。図４（ａ）に前記ランナバンド１ｂ側の最
大羽根厚みＴmaxBが前記ランナクラウン１ａ側の最大羽
根厚みＴmaxAの８０%になっているランナ１の最大羽根
厚みＴmaxの分布を示す。このように最大羽根厚みＴmax
を図４（ｂ）の要部斜視図に示すように、 ＴmaxA＞ＴｍａｘＢ となるような形状に設定することができる。The maximum blade thickness Tmax in the configuration of the bulging portion B does not need to be constant between the runner crown 1a side and the runner band 1b side of the blade 1c, but changes continuously so as to conform to the specification of the water turbine. And a predetermined distribution may be provided. FIG. 4A shows a distribution of the maximum blade thickness Tmax of the runner 1 in which the maximum blade thickness TmaxB on the runner band 1b side is 80% of the maximum blade thickness TmaxA on the runner crown 1a side. Thus, the maximum blade thickness Tmax
Can be set to a shape such that TmaxA> TmaxB as shown in the perspective view of the main part of FIG.

【００２５】また、前記膨らみ部Ｂの構成における羽根
厚みが最大（Ｔｍａｘ）となる位置の頂部Ｒから羽根前
縁Ｐまでの長さＬmaxは羽根１ｃのランナクラウン１ａ
側とランナバンド１ｂ側の間で一定である必要はなく、
水車の仕様に適合するように分布を持たせても良い。図
５（ａ）にはランナバンド１ｂ側の頂部Ｒから羽根前縁
Ｐまでの長さＬmaxBがランナクラウン１ａ側の長さＬma
xAの１５０%になっているランナ１の頂部Ｒから羽根前
縁Ｐまでの長さＬmaxの分布を示す。このように前記長
さＬmaxを図５（ｂ）の要部斜視図に示すように、 ＬmaxA＞ＬmaxB となるような形状に設定することができる。The length Lmax from the top R at the position where the blade thickness is maximum (Tmax) to the blade front edge P in the configuration of the bulging portion B is the runner crown 1a of the blade 1c.
It is not necessary to be constant between the side and the runner band 1b side,
The distribution may be provided so as to conform to the specification of the water turbine. In FIG. 5A, the length LmaxB from the top R on the runner band 1b side to the blade leading edge P is the length Lma on the runner crown 1a side.
The distribution of the length Lmax from the top R of the runner 1 to 150% of xA to the blade leading edge P is shown. In this way, the length Lmax can be set to a shape such that LmaxA> LmaxB as shown in the perspective view of the main part of FIG.

【００２６】さらに、設計の仕様に応じて、図４（ｂ）
と図５（ｂ）に示した形状を組み合わせてもよい。Further, according to the design specifications, FIG.
And the shape shown in FIG. 5B may be combined.

【００２７】次に図６ないし図８を参照して膨らみ部Ｂ
を形成した範囲と羽根後面１ｐの圧力変化の関係につい
て説明する。図６は前記Ｌ75／Ｔmaxを８にして、前記
膨らみ部Ｂにおいて羽根厚みが最大Ｔmaxとなる前記頂
部Ｒから前記羽根前縁Ｐまでの長さＬmaxを変化させた
場合の羽根後面１ｐの圧力変化を流れ解析手法により評
価したものである。図の縦軸はキャビテーションが発生
しない Ｌmax／Ｔmax＝２のときの羽根後面１ｐの圧力
Ｐ0を基準にした無次元圧力である。図から分かる通り
Ｌmax／Ｔmaxが６を超えると圧力低下が著しい。したが
って、Ｌmax／Ｔmaxが６以下となるように頂部Ｒから羽
根前縁Ｐまでの長さＬmaxを設定して膨らみ部Ｂを構成
することが望ましい。Next, referring to FIG. 6 to FIG.
The relationship between the range in which is formed and the pressure change on the blade rear surface 1p will be described. FIG. 6 shows the pressure change of the rear surface 1p of the blade when the length Lmax from the top R to the front edge P of the blade at which the blade thickness is the maximum Tmax at the bulging portion B is changed to 8 at L75 / Tmax. Was evaluated by the flow analysis method. The vertical axis in the figure is a dimensionless pressure based on the pressure P0 of the blade rear surface 1p when cavitation does not occur and Lmax / Tmax = 2. As you can see from the figure
When Lmax / Tmax exceeds 6, the pressure drop is remarkable. Therefore, it is desirable to configure the bulging portion B by setting the length Lmax from the top R to the blade front edge P such that Lmax / Tmax is 6 or less.

【００２８】図７は前記Ｌmax／Ｔmaxを２にして、前記
長さＬ75を変化させた場合の前記羽根後面１ｐの圧力変
化を流れ解析手法により評価したものである。図の縦軸
はキャビテーションが発生しない Ｌ75／Ｔmax =８の羽
根後面１ｐの圧力Ｐ0を基準にした無次元圧力である。
図から分かる通りＬ75／Ｔmaxが４未満では圧力低下が
著しい。したがって、Ｌ75／Ｔmaxが４以上になるよう
にＬ75を設定して膨らみ部Ｂを構成することが望まし
い。FIG. 7 shows the result of evaluating the pressure change on the rear face 1p of the blade when the length L75 is changed by setting Lmax / Tmax to 2, by a flow analysis method. The vertical axis in the figure is a dimensionless pressure based on the pressure P0 of the blade rear surface 1p where L75 / Tmax = 8 where cavitation does not occur.
As can be seen from the figure, when L75 / Tmax is less than 4, the pressure drop is remarkable. Therefore, it is desirable to configure L75 so that L75 / Tmax becomes 4 or more to form the bulging portion B.

【００２９】図８は前記Ｌmax／Ｔmaxを２にして、前記
長さＬ75を変化させた場合の膨らみ部Ｂの裏側に当たる
羽根前面１ｓの流速変化を流れ解析手法により評価した
ものである。図の縦軸はキャビテーションが発生しない
Ｌ75／Ｔmax =８の羽根前面１ｓの流速Ｗ0を基準にし
た無次元流速である。前記長さＬ75が大きくなると羽根
前縁Ｐの羽根間流路１ｗが最短距離Ｓとなる位置Ｑにお
ける羽根厚みが大きくなるため、最短距離Ｓが小さくな
り流速が増加する。図８から分かる通り、流速の増加は
Ｌ75／Ｔmaxが１０以上で生じる。流速が増加すると水
力損失も増大する。したがって、羽根後面１ｐの圧力が
低下せず、かつ、水力損失も増大しないようにするに
は、Ｌ75／Ｔmaxが４以上１０未満であるように膨らみ
部Ｂを構成することが望ましい。FIG. 8 is a graph showing an evaluation of a change in flow velocity at the blade front surface 1s corresponding to the back side of the bulging portion B when the length L75 is changed by setting Lmax / Tmax to 2, using a flow analysis technique. The vertical axis in the figure is the dimensionless flow velocity based on the flow velocity W0 of the blade front surface 1s where L75 / Tmax = 8 where cavitation does not occur. When the length L75 is increased, the blade thickness at the position Q where the inter-blade flow path 1w of the blade leading edge P is the shortest distance S increases, so that the shortest distance S decreases and the flow velocity increases. As can be seen from FIG. 8, the increase in flow velocity occurs when L75 / Tmax is 10 or more. As the flow rate increases, so does the hydraulic loss. Therefore, in order to prevent the pressure at the blade rear surface 1p from decreasing and the hydraulic power loss not increasing, it is desirable to configure the bulging portion B so that L75 / Tmax is 4 or more and less than 10.

【００３０】すなわち、 Ｌmax／Ｔmax≦６ ４≦Ｌ75／Ｔmax＜１０ Ｌ75＞ Ｌmax となるように、長さＬmax、Ｌ75及び羽根厚みＴmaxを設
定すればよい。That is, the lengths Lmax and L75 and the blade thickness Tmax may be set such that Lmax / Tmax ≦ 64 ≦ L75 / Tmax <10 L75> Lmax.

【００３１】[0031]

【発明の効果】以上の説明から明らかなように、本発明
によれば羽根の水車運転時の水流に対して最先端に位置
する前縁部から水車運転時の回転方向に先行する隣接し
た羽根に対して最短距離に当たる位置と、当該隣接した
羽根の前縁部との間に羽根の後面に沿って流れる水流の
剥離を抑制するための膨らみ部を設けたので、ポンプ最
高揚程と水車最低落差の比である変落差比が大きいポン
プ水車の低落差状態の水車運転時でも、ランナ羽根後面
入口の圧力低下を抑制することができる。これによっ
て、キャビテーション性能を向上でき水車運転範囲を大
幅に拡大することができる。As is apparent from the above description, according to the present invention, adjacent blades that precede in the rotational direction during the operation of the turbine from the leading edge located at the forefront with respect to the water flow during the operation of the turbine. A bulge portion between the position corresponding to the shortest distance and the leading edge of the adjacent blade to suppress separation of the water flow flowing along the rear surface of the blade. The pressure drop at the rear face inlet of the runner blade can be suppressed even during the operation of the pump turbine having a large head ratio, which is the ratio of the water turbine, in the low head state. As a result, the cavitation performance can be improved, and the operation range of the water turbine can be greatly expanded.

【００３２】また、本発明によれば、膨らみ部はポンプ
運転時に増速傾向にある場所に設けられており、ポンプ
運転時の流れに影響を及ぼすことがない。これにより、
ポンプ効率を従来通り確保可能である。Further, according to the present invention, the bulging portion is provided in a place where the speed tends to increase during the operation of the pump, and does not affect the flow during the operation of the pump. This allows
Pump efficiency can be secured as before.

【００３３】さらに、本発明によれば、膨らみ部は水車
回転方向に対し羽根後面に設けられており羽根前面には
設けられていないので、前記羽根間流路面積が小さくな
ることはない。これにより、羽根間流路における流速は
増大しないので水力損失も増加しない。その結果、水車
効率を低下させることなく低落差状態でも羽根入口キャ
ビテーションを抑制することができ、水車運転範囲を大
幅に拡大することができる。Further, according to the present invention, the bulging portion is provided on the rear surface of the blade in the rotating direction of the water turbine and is not provided on the front surface of the blade, so that the flow area between the blades does not decrease. Accordingly, the flow velocity in the flow path between the blades does not increase, so that the hydraulic power loss does not increase. As a result, cavitation at the blade entrance can be suppressed even in a low head state without lowering the efficiency of the turbine, and the operating range of the turbine can be greatly expanded.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の第１の実施形態に係るポンプ水車のラ
ンナの羽根形状を示す断面図である。FIG. 1 is a cross-sectional view showing a blade shape of a runner of a pump turbine according to a first embodiment of the present invention.

【図２】図１のポンプ水車のランナの羽根形状の構成を
示す断面図である。FIG. 2 is a sectional view showing a blade-shaped configuration of a runner of the pump turbine of FIG.

【図３】本発明の作用を示す模式図である。FIG. 3 is a schematic view showing the operation of the present invention.

【図４】本発明の第２の実施形態に係るポンプ水車のラ
ンナの羽根形状の構成を示す図である。FIG. 4 is a view showing a blade-shaped configuration of a runner of a pump turbine according to a second embodiment of the present invention.

【図５】本発明の第３の実施形態に係るポンプ水車のラ
ンナの羽根形状の構成を示す図である。FIG. 5 is a view showing a blade-shaped configuration of a runner of a pump-turbine according to a third embodiment of the present invention.

【図６】本発明の実施形態における流れ解析結果を示す
Ｌmax／Ｔmax−Ｐ／Ｐ0の関係を示す特性図である。FIG. 6 is a characteristic diagram showing a relationship of Lmax / Tmax-P / P0 showing a flow analysis result in the embodiment of the present invention.

【図７】本発明の実施形態における流れ解析結果を示す
Ｌ75／Ｔmax−Ｐ／Ｐ0の関係を示す特性図である。FIG. 7 is a characteristic diagram showing a relationship of L75 / Tmax-P / P0 showing a flow analysis result in the embodiment of the present invention.

【図８】本発明の実施形態における流れ解析結果を示す
Ｌ75／Ｔmax−Ｗ／Ｗ0の関係を示す特性図である。FIG. 8 is a characteristic diagram showing a relationship of L75 / Tmax-W / W0 showing a flow analysis result in the embodiment of the present invention.

【図９】従来のポンプ水車の構造を示す断面図である。FIG. 9 is a sectional view showing the structure of a conventional pump turbine.

【図１０】水車運転範囲を示す模式図である。FIG. 10 is a schematic diagram showing a water turbine operation range.

【図１１】従来のポンプ水車のランナの羽根形状を示す
断面図である。FIG. 11 is a sectional view showing a blade shape of a runner of a conventional pump-turbine.

【符号の説明】[Explanation of symbols]

１ 水車ランナ １a ランナクラウン １b ランナバンド １c 羽根 １s 羽根前面 １p 羽根後面 １ｗ 羽根間流路 ２ ガイドベーン ３ ステーベーン ４ ケーシング ５ 回転軸 ６ 吸出し管 ７ ガイドベーンの翼そり線 Ｂ 膨らみ部 Ｐ 羽根前縁 Ｑ 羽根前縁の羽根間距離が最短となる隣羽根の対応点 Ｒ 羽根後面に設けられた膨らみ部の頂点 Ｓ 羽根前縁の最短羽根間距離 Ｔmax 羽根後面に設けられた膨らみ部の最大羽根厚み Ｌmax 羽根後面に設けられた膨らみ部の最大羽根厚み
点と羽根前縁の距離 Ｌ75 羽根厚みが膨らみ部の最大羽根厚みの７５％にも
どる点と羽根前縁との距離DESCRIPTION OF SYMBOLS 1 Turbine runner 1a Runner crown 1b Runner band 1c Blade 1s Front of blade 1p Rear surface of blade 1w Flow path between blades 2 Guide vane 3 Stay vane 4 Casing 5 Rotating shaft 6 Suction pipe 7 Guide vane swelling line B Bulging portion P Blade leading edge Q Corresponding point of the adjacent blade where the distance between the blades at the leading edge of the blade is the shortest R Apex of the bulging portion provided at the rear surface of the blade S Minimum distance between the shortest blades at the leading edge of the blade Tmax Maximum blade thickness Lmax of the bulging portion provided at the rear surface of the blade Distance between the maximum blade thickness point of the bulge provided on the rear surface of the blade and the leading edge of the blade L75 Distance between the point where the blade thickness returns to 75% of the maximum blade thickness of the bulge and the blade front edge

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 ランナクラウン及びランナバンドによっ
て回転軸の回りに複数枚配置された羽根を保持し、各羽
根間に流路を有するランナを備えた水車及びポンプ水車
において、 前記羽根の水車運転時の水流に対して最先端に位置する
前縁部から水車運転時の回転方向に先行する隣接した羽
根に対して最短距離に当たる位置と、当該隣接した羽根
の前縁部との間に羽根の後面に沿って流れる水流の剥離
を防止するための膨らみ部を設けたことを特徴とする水
車及びポンプ水車。1. A water turbine and a pump turbine having a runner having a plurality of blades arranged around a rotation axis by a runner crown and a runner band, and having a runner having a flow path between the blades. The rear surface of the blade between a position that is the shortest distance from the leading edge positioned at the forefront to the water flow to the adjacent blade preceding in the rotation direction during the operation of the turbine and the front edge of the adjacent blade. A water turbine and a pump water turbine provided with a bulging portion for preventing separation of a water flow flowing along a water wheel. 【請求項２】 前記膨らみ部が羽根厚みが最大となる頂
部から前記最短距離に当たる位置までの前記羽根後面に
変曲点を備えていることを特徴とする請求項１記載の水
車及びポンプ水車。2. A water turbine and a pump-turbine according to claim 1, wherein the bulging portion has an inflection point on a rear surface of the blade from a top where the blade thickness is maximum to a position corresponding to the shortest distance. 【請求項３】 前記膨らみ部の羽根厚みが最大となる頂
部の羽根厚みをＴmax、前記羽根前縁から前記頂部まで
の長さをＬmax、水車運転時の水流に対し前記頂部の下
流側で羽根厚みが前記頂部の羽根厚みＴmaxの７５%に戻
る部分と前記羽根前縁までの長さをＬ75としたとき、 前記長さＬmaxと前記羽根厚みＴmaxの比が、 Ｌmax／Ｔmax≦６ であり、前記長さＬ75と前記羽根厚みＴmaxとの比が、 ４≦Ｌ75／Ｔmax＜１０ であり、かつ、前記長さＬ75とＬmaxとの比が、 Ｌ75＞ Ｌmax となるように前記長さＬmax、Ｌ75及び羽根厚みＴmaxが
設定されていることを特徴とする請求項１記載の水車及
びポンプ水車。3. The blade thickness of the top portion where the blade thickness of the bulging portion is maximum is Tmax, the length from the leading edge of the blade to the top portion is Lmax, and the blades are located downstream of the top portion with respect to the water flow during operation of the turbine. When the length between the portion where the thickness returns to 75% of the blade thickness Tmax at the top and the blade leading edge is L75, the ratio of the length Lmax to the blade thickness Tmax is Lmax / Tmax ≦ 6, The lengths Lmax and L75 are such that the ratio between the length L75 and the blade thickness Tmax is 4 ≦ L75 / Tmax <10, and the ratio between the lengths L75 and Lmax is L75> Lmax. The turbine and the pump turbine according to claim 1, wherein a blade thickness Tmax is set. 【請求項４】 前記頂部の羽根厚みＴmaxが、前記ラン
ナクラウンと前記ランナバンドの間で連続的に変化して
いることを特徴とする請求項３記載の水車及びポンプ水
車。4. A water turbine and a pump-turbine according to claim 3, wherein the blade thickness Tmax at the top portion changes continuously between the runner crown and the runner band. 【請求項５】 前記長さＬmaxが、前記ランナクラウン
と前記ランナバンドの間で連続的に変化していることを
特徴とする請求項３記載の水車及びポンプ水車。5. A water turbine and a pump-turbine according to claim 3, wherein the length Lmax continuously changes between the runner crown and the runner band.
JP10153031A 1998-06-02 1998-06-02 Hydraulic turbine and reversible pump-turbine Pending JPH11343955A (en)

Priority Applications (1)

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JP10153031A JPH11343955A (en) 1998-06-02 1998-06-02 Hydraulic turbine and reversible pump-turbine

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JP10153031A JPH11343955A (en) 1998-06-02 1998-06-02 Hydraulic turbine and reversible pump-turbine

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6820333B2 (en) 2002-03-27 2004-11-23 Hitachi, Ltd. Method of converting storage pumps into reversible pump-turbines
JP2006291865A (en) * 2005-04-12 2006-10-26 Toshiba Corp Hydraulic machine runner and hydraulic machine
JP2011052663A (en) * 2009-09-04 2011-03-17 Mitsubishi Heavy Ind Ltd Runner and fluid machine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6820333B2 (en) 2002-03-27 2004-11-23 Hitachi, Ltd. Method of converting storage pumps into reversible pump-turbines
JP2006291865A (en) * 2005-04-12 2006-10-26 Toshiba Corp Hydraulic machine runner and hydraulic machine
JP2011052663A (en) * 2009-09-04 2011-03-17 Mitsubishi Heavy Ind Ltd Runner and fluid machine

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